1. Field of the Invention
The present invention relates to hand-held devices, commonly called pipet guns, wherein fluids are drawn into and thereafter expelled from pipets for medical and other uses.
2. Background Art
Although generally much larger in size, there are a number of prior art devices which use suction to draw fluids into attached pipets and thereafter expel such fluids from such pipet. See, e.g., my U.S. Pat. Nos. 3,963,061, 3,834,240 and 4,624,147, all of which are incorporated herein by reference.
As described in my previous patents, the practice of drawing liquids into pipets by mouth can be dangerous and the practice has been prohibited in many laboratories.
Pipet guns heretofore devised overcome this health problem, but are heavy and large. Since the operator must draw a large number of samples, there is a true need for a hand-held unit which is light to avoid fatigue and which does not have to be connected to any number of auxiliary devices or supply sources, such as an air pressure and vacuum pump.
In short, there is a real need for a pipet gun which is small, such that the hand grip can be easily held even by a small hand, which is light, yet which has a very powerful air and suction unit.
Pipet guns have been developed with self-contained air/vacuum supply units. However, these units are overly large and unwieldy and are very heavy.